1. Field of the Invention
The present invention relates to an apparatus, method and computer program, for rotating, moving, scaling up or down or otherwise manipulating a three-dimensional object on a display screen by a dial-operated input device.
This application claims the priority of the Japanese Patent Application No. 2003-050059 filed on Feb. 26, 2003, the entirety of which is incorporated by reference herein.
2. Description of the Related Art
Generally, a pointing device such as a mouse or the like is used to rotate, move, scale up or down or otherwise manipulate a three-dimensional object displayed on a display screen. With the pointing device like the mouse, the user can intuitively make a pointing operation with a high degree of freedom because a movement of the user's hand or finger precisely results in a movement of a pointing cursor on the display screen.
Also, there are well known a mouse having additionally provided on the body thereof a dial which supplies another scale factor at which an image is to be displayed on a display screen (as disclosed in the Japanese Published Unexamined Patent Application No. 1993-108263, FIG. 1, for example) and a mouse having additionally provided on the body thereof a rotation unit whose operation is combinable with operations of the mouse itself to provide various events (as disclosed in the Japanese Published Unexamined Patent Application No. 1996-161098, FIG. 2, for example), etc.
However, the pointing device such as a mouse can only be used smoothly and comfortably in an ample operating space. There will arise no problem with a pointing device which is used with an apparatus to which a variety of peripheral devices is to be connected, such as a personal computer or the like. But the pointing device is not suitable for use with a portable information device such as a mobile phone or PDA (portable digital assistant) as well as with a portable electronic appliance such as digital video camcorder (=camera/recorder) or the like.
Many of recent portable electronic appliances such as the portable phone, PDA, digital video camcorder, etc. have installed therein a dial-operated input device with a jog dial as an input device to enable the user to select an object such as an icon or the like in a menu screen. The dial of the dial-operated input device can be pushed in and freely rotated. When the user pushed in and rotates the dial with the finger being applied to the perimeter of the dial, for example, the dial-operated input device generates input signals corresponding to a direction and angle of the dial rotation. Since the dial-operated input device can simply be constructed, it can easily be incorporated in a display unit, electronic appliance body or the like and it needs only a small operating space. Namely, the input device of this type can be said to be suitable for use with the above-mentioned portable electronic appliance.
On the other hand, however, since the dial-operated input device is inferior in degree of freedom of pointing operation to the mouse, it is not suitable for defining an arbitrary axis of rotation of a three-dimensional object, rotating the three-dimensional object about the axis of rotation and moving the three-dimensional object in an arbitrary direction.